硅微光机械加速度地震检波器中 M-Z光波导干涉仪结构设计

提出了一种新型的硅基M-Z干涉型光电集成加速度地震检波器。对硅基微光电机械加速度地震检波器的M-Z光波导干涉仪系统进行了系统研究和优化设计,采用K9玻璃作为基底层和包层材料,Bak7玻璃作为波导层材料,波导的宽度为4 μm,厚度为0.4 μm。M-Z光波导干涉仪的Y分支设计中采用上升反正弦S型弯曲,为适用于该干涉仪的信号臂和参考臂大跨距的特殊结构,应用波导转向镜实现了大角度光路转折,反射转向镜的内介质采用镀制金属铝膜得以实现,并利用BPM进行了仿真。为了防止TE模偏振光的偏振态经铝膜全反射后发生变化,加了4个长度为1 mm的TE模偏振器以保持其偏振态。实验结果与理论相符。

Structure design of Mach-Zehnder interferometer in electrooptic integrated acceleration seismic geophone

A novel electrooptic integrated acceleration seismic geophone was presented. Mach-Zehnder waveguide interferometer of Si-based MOEMS (micro-opto-electro-mechanical system)acceleration seismic geophone was researched and its optimization structure design was accomplished. The material of buffer layer and coating layer is K9 glass. Two Bak7 glass Y-branching waveguides with width of 4 μm and thickness of 0.4 μm, and six guide mirrors are employed in interferometer. A S-shaped curve is used for the transition connecting two offset parallel waveguides in Y-branching. Because it is difficulty to make the branching angle large enough by using conventional Y-branching, a 90° directional change by a vertical mirror facet to realize the special structure between measuring arm and reference arm is designed. The inner dielectric film of the mirror facet is aluminum plating. To prevent the polarization state of TE mode polarized light from changing after passing through the aluminum film,4 polarizers with length of 1 mm have been used. The simulation results performed in BPM and the experiment agrees with the theoretical analysis well.